1. Field of the Invention
This invention relates to an improved process for manufacture of acid cheese curd in conventional dairy equipment without using bacterial fermentation.
2. Description of the Prior Art
Various processes for preparing cheese from chemically acidified milk without using bacterial fermentation are known. U.S. Pat. No. 3,620,768 (Corbin) teaches the acidification of cold milk at about 0.degree. C. to about 7.2.degree. C. to a pH of about 5.20 to about 4.88 using a free acid such as lactic acid, phosphoric acid, citric acid, acetic acid, maleic acid, sulfuric acid, hydrochloric acid, succinic acid or the like. British Pat. No. 1,247,415 (Battelle) also teaches the acidification of cold milk, and moreover states at page 3, lines 3 through 7, that: "It is well known that when milk is acidified at a temperature of about 70.degree. F. (21.degree. C.) to a pH of about 5.20 or below, it coagulates almost instantly into a granular water coagulation, totally unfit for making cheese." This disclosure is supported, generally, in "Principles of Dairy Chemistry" by Robert Jenness and Stuart Patton (John Wiley and Sons, New York, 1959) at page 310, where it is stated: ". . . the sensitivity of casein to coagulation by heat is enormously increased by decreasing the pH a few tenths of a unit below the normal value for milk."
U.S. Pat. No. 3,882,250 (Loter et al) teaches the acidification of vigorously agitated milk at about 15.degree. C. to about 30.degree. C. to a pH of about 5.00 by adding 10 to 90 percent aqueous solution of free acid such as lactic acid, phosphoric acid, citric acid, acetic acid, maleic acid, sulfuric acid, hydrochloric acid, succinic acid or the like. An acidogen and proteolytic enzyme are then mixed with the acidified milk of about 15.degree. C. to about 30.degree. C. and the mixture allowed to stand quiescent at the same temperature for about 30 minutes to about 4 hours so as to form an acid cheese curd suitable for making cottage cheese, baker's cheese, quark cheese, cream cheese and Neufchatel cheese.